Contra-Gravity Drive
''"Sure there's Fundamental Forces in the Universe, And of these Gravity is supposed to be the weakest. But when somebody trips over a chair in the middle of the night you don't hear them cursing Electromagnetics at the top of their lungs now do you?" '' ~Study in forces on the "Doctor Roy's Science Hour" Holo show. ---- The Way it Works Contra-gravity drives (or the vulgar: Repulsar fields) are mentioned elsewhere in the Atmospheric Transports section as being the usual lift mechanism that a modern society uses to get items and transports off the ground. Contra-gravity fields work fairly simply. Once powered up, the generator creates a form of gravity Cushion beneath the object. Simulating the effects of a gravity mass in the opposite direction from the local center which causes the vehicle to be acted upon by both directions of forces. Since the field is generated in relation to the projecting object and local mass of gravity at a constant power ratio of 1 to 1 it allows for the object to "fall" upwards at the same time it's "falling" Downwards thus creating a neutral buoyancy state. Changing the power output of the drive allows the vehicle to raise, lower or maintain itself in relation to the local gravity mass. For most planets there are several gravity zones, the largest of being (within an atmosphere) the Near GL zone which is where the gravity tends to remain at a constant level. As the height progresses (And the atmosphere gets much thinner) the amount of energy needed for a contra-gravity field to lift more mass lessens. Most systems will have an automatic compensator built in that will relegate the power output for vehicles as they move further outside the close gravity zone. One in Zero gravity (or a position outside the visual recordable pull of the local gravitic mass to effectively have negated the pull of such mass upon the smaller) starships use Contra-Gravity field generators in the form of a Gravimetric Drive. Not to be confused with a Traction drive, Gravimetric drives work similarly to Contra-gravity fields in that they cause the ship to "fall" towards the direction of orientation. Once in a space (or the vulgar Zero-G) environment the ship can continue to "fall" indefinitely towards the direction the field is focused. Some times several fields will be working at the same time akin to an hourglass configuration where the ship is at the bottleneck and constantly "falling" forward towards one side of the glass, while separate fields on the other end will work in reverse "pushing" the ship as well. The configuration used all depends on just how much energy the captain intends to use for acceleration, and once the ship has built up sufficient inertia the fields can be powered down till course adjustments are needed. ---- Benefits & Disadvantages Gravimetrics have several benefits, first among such is that vehicles are able to operate in an atmosphere and space equally since it's all dependent on mass and energy utilized. Instead of needing huge thrusters to lift off a planet's surface and land, they just need more power put into the field for larger craft. Also for ships making use of such fields they do not need to have large "wing" surfaces for providing lift, in fact the only purposes such additions provide is in the form of improving maneuvering for such a vehicle. It also provides inertial dampening fields which are a form of contra-gravity field that operates (for the most part) within a "crew/passenger section" of the vehicle which creates a counter balancing field to inertial forces thus allowing for faster acceleration without inertial compression of the squishy tissue most beings are made of. A sensor reads the inertial force that will be enacting on the passengers and creates a countering force of usually equal magnitude (though for those who get disoriented by a feeling of "not moving" tend to set their compensators slightly lower so they can "feel" like their accelerating or moving) that maintains "being integrity". The inertial dampening field is a necessity especially for space travel where the sudden acceleration of sublight engines could turn many of the crew into smears of tissue with the sudden acceleration. The final advantage of primary interest to other means of conveyance is the ability to create an artificial gravity field on board a ship. Usually in the form of Variable gravity plating, gravity nets, or Older style Grav-field generators no longer do crews in ships need to be concerned with being in space and either needing magnetic footwear or other contraptions, or muscle deterioration due to lessened gravity. Disadvantage wise, acceleration can be dismally slow. Even with the field boosted to the equivalent of a 7 or 8 G planet, mass can only accelerate so fast with gravity power alone. Additionally various atmospheric conditions and densities can limit just what maximum velocity is available for a Gravimetric drive. Once the atmosphere is thinner naturally this velocity changes, but for a hasty departure from a planetary atmosphere it can put a bit of a damper on such. They also have the same disadvantage in slowing down once one reaches velocity. Such ships are rarely able to "Stop on a Duckat" or make really tight turns once the inertial forces have built up from acceleration. Finally local gravity sources, such as black holes, dark-matter asteroids, dense stellar objects or Mass packet warheads will work to throw off the Gravimetric drive unless compensated for or cleared. To bypass a lot of these drawbacks ships that primarily use a Gravimetric drive will also equip their ship with an additional thruster system of some sort for the extra "push" when needed.